Eccentric valve

ABSTRACT

An eccentric valve has a drive mechanism, a drive force receiving part, a bearing for supporting a rotary shaft, and a return spring for generating a return spring force. During non-operation of the drive mechanism, the eccentric valve generates a separating-direction urging force to cause the rotary shaft to incline about the bearing serving as a fulcrum and urge the valve element in a direction away from the valve seal, the separating-direction urging force being a force caused by the return spring force. Either the valve element or the valve seat is provided with a sealing member to seal between the valve element and the valve seat during non-operation of the drive mechanism.

CROSS REFERENCE TO RELATED APPLICATIONS

This is a divisional application of U.S. Ser. No. 15/768,861, which wasa U.S. national phase application based on the PCT International PatentApplication No. PCT/JP2016/077294 filed on Sep. 15, 2016, and claimingthe priority of Japanese Patent Application No. 2015-253259 filed onDec. 25, 2015, the entire contents of which are herewith incorporated byreference.

TECHNICAL FIELD

The present invention relates to an eccentric valve (a double eccentricvalve), which is a valve to be used as a flow control valve, in which avalve element is placed with its rotation center (a rotary shaft)positioned eccentrically from a center of a valve hole of a valve seat,and a seal surface of the valve element is positioned eccentrically fromthe rotary shaft.

BACKGROUND ART

For a flow control valve, Patent Document 1 discloses a flow open/closevalve configured to come into a valve-closed slate by rotating u valveelement into contact with a movable seat or come into a valve-open stateby rotating the valve element away from the movable seat.

RELATED ART DOCUMENTS Patent Documents

-   -   Patent Document 1: Japanese Unexamined Patent Application        Publication No. 2012-72793

SUMMARY OF INVENTION Problems to be Solved by the Invention

However, in the flow open/close valve in Patent Document 1, the valveelement is merely in contact with the movable seat in the valve-closedstate where a drive source is not operated. Thus, in the valve-closedstate, scaling property between the valve element and the movable sealcould not be enhanced (a sealing function could not be fulfilled).

The present invention has been made to solve the above problems and hasa purpose to provide an eccentric valve capable of enhancing a sealingproperty in a valve-closed state.

Means of Solving the Problems

To achieve the above purpose, one aspect of the invention provides aneccentric valve comprising: a valve seat including a valve hole and aseat surface formed at an edge of the valve hole; a valve element formedwith a seal surface on an outer periphery corresponding to the seatsurface; a rotary shaft integrally provided with the valve element torotate the valve element, and the rotary shaft having a central axisextending in parallel to a radial direction of the valve element, thecentral axis of the rotary shaft being positioned eccentrically from acenter of the valve hole in another radial direction of the valve hole,and the seal surface being positioned eccentrically from the centralaxis of the rotary shaft toward an extending direction of a central axisof the valve element, wherein the eccentric valve further comprises: adrive mechanism configured to generate a drive force to rotate therotary shaft in a valve opening direction; a drive force receiving partintegrally provided with the rotary shaft and configured to receive thedrive force; a bearing placed in a position between the valve elementand the drive force receiving part in a direction of the central axis ofthe rotary shaft to support the rotary shaft; and a return springconfigured to generate a return spring force to rotate the rotary shaftin a valve closing direction, wherein, during non-operation of the drivemechanism, the eccentric valve generates a separating-direction urgingforce to cause the rotary shaft to incline about the bearing serving asa fulcrum and urge the valve element in a direction away from the valveseat, the separating-direction urging force being a force caused by thereturn spring force and acting in a direction perpendicular to a centralaxis of the bearing, and either the valve element or the valve seat isprovided with a sealing member to seal between the valve element and thevalve seat during non-operation of the drive mechanism.

According to the above configuration, during non-operation of the drivemechanism, the scaling member seals between the valve seat and the valveelement. Thus, a sealing property in the valve-closed state can beenhanced.

In the foregoing configuration, preferably, the sealing member includesa deformable portion having a leading end that comes into contact withthe valve element or the valve seat during non-operation of the drivemechanism and that is deformed when pressed by the valve element or avalve seat during operation of the drive mechanism, and a deformationamount of the deformable portion during operation of the drive mechanismis smaller than a deformation amount of the deformable portion whenplastically deformed.

According to the above configuration, the deformable portion of thesealing member is not excessively pressed by the valve element. Thus,abrasion or wear of the sealing member can be reduced.

In the foregoing configuration, preferably, when the drive mechanism isto be switched from an operation state to a non-operation state, thedrive mechanism is switched to the non-operation state after a pressureon the valve element on a side facing the valve seat, reaches apredetermined negative pressure.

According to the above configuration, the drive mechanism is operateduntil the pressure exerted on the valve element on the side facing tothe valve seat (a valve-seat side) reaches the predetermined negativepressure. After the pressure exerted on the valve element on thevalve-seat side has reached the predetermined negative pressure, thedrive mechanism is not operated and the valve element is caused to movetoward the valve seat by utilization of the negative pressure generatedon the valve-seat side with respect to the valve element. Thus, a highsealing property can be achieved between the valve seal and the valveelement.

In the foregoing configuration, preferably, the eccentric valve isconfigured to perform a control mode during operation of the drivemechanism, the control mode including a pressure-regulating mode forcontrolling an open area of the valve hole and a scaling control modefor controlling rotation of the valve element near a fully-closedposition of the valve element.

According to the above configuration, the rotation of the valve elementnear a fully-closed position of the valve element is performed only inthe sealing control mode. Thus, the number of limes the valve elementand the sealing member slide on each other can be reduced. Thus,abrasion or wear of the sealing member can be reduced.

In the foregoing configuration, preferably, a rotation speed of thevalve element in the sealing control mode is slower than a rotationspeed of the valve element in the pressure-regulating mode.

According to the above configuration, the strength of sliding of thevalve element with respect to the sealing member in the sealing controlmode can be reduced. Thus, abrasion or wear of the scaling member can bereduced.

In the foregoing configuration, preferably, the valve element and thesealing member in the pressure-regulating mode are in a non-contactstale with each other.

According to the above configuration, in which the valve element and thesealing member are not in contact with each other in thepressure-regulating mode which is frequently performed, the number oftimes the valve element and the sealing member slide against each othercan be minimized. Thus, abrasion or wear of the sealing member can bereduced.

In the foregoing configuration, preferably, the eccentric valve isprovided with a passage through which air in a fuel cell system flows,and when the fuel cell system drives an air pump to control a flow rateof the air in response to a regenerative brake request, an openingdegree of the valve element is maintained at an opening degree within anopening degree range determined in the sealing control mode.

According to the above configuration, the frequency of sliding of thevalve element and the sealing member can be reduced. Therefore, whileabrasion of the scaling member is suppressed, surplus electric powergenerated at the time of a regenerative brake request can be consumedfor operating an air pump.

Effects of the Invention

According to an eccentric valve of the present invention, a sealingproperly in a valve-closed state can be enhanced.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic configuration view of a fuel cell system;

FIG. 2 is a front view of an integrated valve in an embodiment;

FIG. 3 is a top view of the integrated valve in the embodiment;

FIG. 4 is a partially-cutaway perspective view of a valve unit in avalve-closed state (a fully-closed state) where a valve element is incontact with a valve seat;

FIG. 5 is a partially-cutaway perspective view of the valve unit in afully-open stale where the valve element is separated furthest from thevalve seat;

FIG. 6 is a side view of the valve seat, the valve element, and a rotaryshaft in the fully-closed state of a flow control valve;

FIG. 7 is a cross-sectional view taken along a line A-A in FIG. 6;

FIG. 8 is a cross-sectional view taken along a line B-B in FIG. 2;

FIG. 9 is a cross-sectional view taken along a line C-C in FIG. 2;

FIG. 10 is a from view showing a state where an end frame has beendetached from a valve housing;

FIG. 11 is on enlarged view (a partially-cutaway view) of a main gear, areturn spring, and an intermediate gear during non-operation of a motor;

FIG. 12 is a schematic view showing forces acting on the main gearduring non-operation of the motor and seen from a main gear side in acentral axis direction of a rotary shaft;

FIG. 13 is a schematic view representing the valve seat, the valveelement, the rotary shaft, bearings, and the main gear, showing across-sectional view taken along a line D-D in FIG. 12;

FIG. 14 is a schematic view showing forces acting on the main gearduring operation of the motor and seen from the main gear side in thecentral axis direction of the rotary shaft;

FIG. 15 is a schematic view representing the valve seat, the valveelement, the rotary shaft, the bearings, and the main gear, showing across-sectional view taken along a line E-E in FIG. 14:

FIG. 16 is a diagram corresponding to FIG. 15, and representing a casewhere a motor drive force is set larger than that in FIG. 15;

FIG. 17 is an enlarged view (a partially-cutaway view) of the main gear,the return spring, the intermediate gear, and their surrounding parts ata valve opening degree of a during operation of the motor;

FIG. 18 is a diagram corresponding to FIG. 16, and representing a casewhere a motor drive force is set larger than that in FIG. 16;

FIG. 19 is an enlarged view (a partially-cutaway view) of the main gear,the return spring, the intermediate gear, and their surrounding parts ata valve opening degree of P during operation of the motor;

FIG. 20 is a graph showing a relationship between valve opening degreeand open area:

FIG. 21 is a view showing a rubber seat;

FIG. 22 is a view showing a rubber seat in a modified example;

FIG. 23 is a view showing a rubber seat in another modified example;

FIG. 24 is a cross-sectional view of the valve seal and the valveelement and their surrounding parts when an opening degree of the valveelement is an angle A;

FIG. 25 is a cross-sectional view of the valve seat and the valveelement and their surrounding parts when the opening degree of the valveelement is an angle B;

FIG. 26 is a control flowchart in a second embodiment;

FIG. 27 is a time chart in the second embodiment;

FIG. 28 is a control flowchart in a third embodiment;

FIG. 29 is a time chart in the third embodiment;

FIG. 30 is a control flowchart in a fourth embodiment; and

FIG. 31 is a time chart in the fourth embodiment.

MODE FOR CARRYING OUT THE INVENTION First Embodiment

The present invention is applied for example to an integrated valve ofan air system in a fuel cell system. Thus, the fuel cell system will bedescribed first and then the integrated valve to which an eccentricvalve of the invention is applied will be described later.

<Description of Fuel Cell System>

A fuel cell system 101 is mounted in an electric vehicle and used tosupply electric power to a drive motor (not illustrated) of the vehicle.As shown in FIG. 1, the fuel cell system 101 includes a fuel cell (FCstack) 111, a hydrogen system 112, and an air system 113.

The fuel cell 111 generates power upon receiving supply of fuel gas andsupply of oxidant gas. In the present embodiment, the fuel gas ishydrogen gas and the oxidant gas is air. Specifically, the fuel cell 111generates power when receives hydrogen gas supplied from the hydrogensystem 112 and air supplied from the air system 113. The electric powergenerated in the fuel cell 111 is supplied to a drive motor (notillustrated) through an inverter (not illustrated).

The hydrogen system 112 is provided on an anode side of the fuel cell111. This hydrogen system 112 is provided with a hydrogen supply passage121, a hydrogen exhaust passage 122, and a filling passage 123. Thehydrogen supply passage 121 is a flow passage for supplying hydrogen gasfrom a hydrogen tank 131 to the fuel cell 111. The hydrogen exhaustpassage 122 is a flow passage for discharging hydrogen gas exhaustedfrom the fuel cell 111 (hereinafter, appropriately referred to as“hydrogen offgas”). The filling passage 123 for filling hydrogen gasinto the hydrogen tank 131 through a fill port 151.

The hydrogen system 112 includes, on the hydrogen supply passage 121, amain slop valve 132, a high-pressure regulator 133, a medium-pressurerelief valve 134, a pressure sensor 135, an injector part 136, alow-pressure relief valve 137, and a pressure sensor 138, which arearranged in this order from the hydrogen tank 131 side. The main stopvalve 132 is a valve for switching between supply and shutoff ofhydrogen gas from the hydrogen tank 131 to the hydrogen supply passage121. The high-pressure regulator 133 is a pressure-regulating valve toreduce the pressure of hydrogen gas. The medium-pressure relief valve134 is a valve configured to open when the pressure in the hydrogensupply passage 121 between the high-pressure regulator 133 and theinjector part 136 becomes a predetermined pressure or higher in order toregulate the pressure to below the predetermined pressure. The pressuresensor 135 is a sensor to detect the pressure in the hydrogen supplypassage 121 between the high-pressure regulator 133 and the injectorpart 136. The injector part 136 is a mechanism for regulating a flowrate of hydrogen gas. The low-pressure relief valve 137 is a valveconfigured to open when the pressure in the hydrogen supply passage 121between (he injector part 136 and the fuel cell stack 111 becomes apredetermined pressure or higher in order to regulate the pressure tobelow the predetermined pressure. The pressure sensor 138 is a sensor todetect the pressure in the hydrogen supply passage 121 between theinjector part 136 and the fuel cell stack 111.

The hydrogen system 112 further includes, on the hydrogen exhaustpassage 122, a gas-liquid separator 141 and an exhaust-drain valve 142arranged in this order from the fuel cell stack 111 side. The gas-liquidseparator 141 is a device to separate moisture from the hydrogen offgas.The exhaust-drain valve 142 is a valve to switch between exhaust andshutoff of hydrogen offgas and moisture from the gas-liquid separator141 to a diluter 182 of the air system 113.

The air system 113 is provided on a cathode side of the fuel cell stacklit. This air system 113 is provided with an air supply passage 161, anair exhaust passage 162, and a bypass passage 163. The air supplypassage 161 is a flow passage to supply air from the outside of the fuelcell system 101 into the fuel cell stack 111. The air exhaust passage162 is a flow passage to exhaust air discharged out of the fuel cell 111(hereinafter, appropriately referred to as “air offgas”). The by-passpassage 163 is a flow passage to allow air to flow from the air supplypassage 161 to the air exhaust passage 162 without passing through thefuel cell 111.

The air system 113 further includes, on the air supply passage 161, anair cleaner 171, an air pump 172, an intercooler 173, and a scalingvalve 174, which are arranged in this order. The air cleaner 171 is adevice to clean up the air taken from outside into the fuel cell system101. The air pump 172 is a device to regulate a flow rate of air. Theintercooler 173 is a device to coot air. The sealing valve 174 is avalve to switch between supply and shutoff of air to the fuel cell 111.

The air system 113 further includes, on the air exhaust passage 162, anoutlet integrated valve 181 and the diluter 182 arranged in this orderfrom the fuel cell 111 side.

The outlet integrated valve 181 is a valve (a valve having a functionthat seals air) to switch between exhaust and shutoff of the air offgasfrom the fuel cell 111 and also a valve (a valve having a function thatcontrols a flow rate) to control an exhaust amount of air offgas fromthe fuel cell 111. In the present embodiment, the eccentric valve of thepresent invention is applied to the integrated valve 181.

The diluter 182 is a device to dilute hydrogen offgas exhausted from thehydrogen exhaust passage 122 by the air offgas and the air flowingthrough the bypass passage 163.

The air system 113 further includes a bypass valve 191 on the bypasspassage 163. The bypass valve 191 is a valve to control a flow rate ofair in the bypass passage 163.

The fuel cell system 101 is further provided with a controller 201 tocontrol the system. Specifically, the controller 201 is configured tocontrol each part or device of the fuel cell system 101. In addition,the fuel cell system 101 also includes a cooling system (not shown) tocool the fuel cell 111. In the present embodiment, the controller 201 isfor example an ECU.

In the fuel cell system 101 configured as above, the hydrogen gassupplied from the hydrogen supply passage 121 to the fuel cell 111 isconsumed in the fuel cell 111 to generate electric power and thereafteris exhausted as hydrogen offgas from the fuel cell 111 to the outside ofthe fuel cell system 101 through the hydrogen exhaust passage 122 andthe diluter 182. The air supplied from the air supply passage 161 to thefuel cell 111 is consumed in the fuel cell 111 to generate electricpower and then is exhausted as air offgas from the fuel cell 111 to theoutside of the fuel cell system 101 through the air exhaust passage 162and the diluter 182.

<Description of Integrated Valve>

Next, the integrated valve 181 to which the eccentric valve of thepresent invention is applied will be described below.

As shown in FIGS. 2 and 3, the integrated valve 181 is provided with avalve section 2 and a drive mechanism section 3. The valve section 2includes a pipe part 12 (see FIG. 8) having a passage 11 for allowingair (atmospheric air) to flow. In this passage 11, there are placed avalve seat 13, a valve element 14, and a rotary shaft 15. The rotaryshaft 15 receives driving force (torque) transmitted from the drivemechanism section 3. This drive mechanism section 3 includes a motor 32and a speed-reducing mechanism 33 (sec FIGS. 8 and 9).

As shown in FIGS. 4 and 5, the passage II is formed with a recessedshoulder 10 in which the valve seat 13 is fitted. The valve seal 13 hasa circular ring shape formed with a valve hole 16 at the center. Thevalve hole 16 is formed, on its circumferential edge, with an annularseat surface 17. The valve element 14 includes a circular disc-shapedportion whose outer periphery has an annular seal surface 18corresponding to the seat surface 17. The valve element 14 is integrallyprovided with the rotary shaft 15 and rotatable together with the rotaryshaft 15.

In the present embodiment, the valve seat 13 is provided with a rubberseat 21. The seat surface 17 is formed in this rubber seat 21. Thedetails of the rubber seal 21 will be described later.

In the present embodiment, referring to FIGS. 4 and 5, the passage 11formed on an opposite side to the valve element 14 and the rotary shaft15 relative to the valve seat 13 is located on a side leading to thefuel cell stack 111 (on an upstream side of air flow), while the passage11 formed on a side closer to the valve element 14 and the rotary shaft15 relative to the valve seat 13 is located on a side leading to thediluter 182 (on a downstream side of air flow). In other words, in thepresent embodiment, the air flow in the passage 11 from the valve seat13 side toward the valve element 14 (the rotary shaft 15) side.

As shown in FIGS. 6 and 7, the central axis Ls of the rotary shaft 15extends in parallel to u radial direction of the valve element 14 (moreconcretely, the diameter of the disc-shaped portion of the valve element14) and is positioned eccentrically from the central axis P1 of thevalve hole 16 to one side in a radial direction of the valve hole 16.The seal surface 18 of the valve element 14 is positioned eccentricallyfrom the central axis Ls of the rotary shaft 15 to an extendingdirection of the central axis Lv of the valve element 14.

By rotation of the valve element 14 about the central axis Ls of therotary shaft 15, the valve element 14 is movable between a valve-closedposition in which the seal surface 18 of the valve element 14 is insurface contact with the seat surface 17 (see FIG. 4) and a fully-openposition in which the seal surface 18 is most away from the seat surface17 (see FIG. 5).

As shown in FIGS. 8 and 9, a valve housing 35 made of either metal orsynthetic resin is provided with the passage 11 and the pipe part 12. Anend frame 36 made of either meal or synthetic resin closes an open endof the valve housing 35. The valve element 14 and the rotary shaft 15are placed in the valve housing 35. The rotary shaft 15 includes a pin15 a in its distal end portion. Specifically, the pin 15 a is providedat one end of the rotary shaft 15 in a direction of the central axis Ls(on the side close to the valve element 14). The diameter of the pin 15a is smaller than the diameter of a portion of the rotary shaft 15 otherthan the pin 15 a. At the other end of the rotary shaft 15 in thedirection of the central axis Ls (on the side close to a main gear 41),there is provided with a proximal end portion 15 b.

The distal end portion of the rotary shaft 15 formed with the pin 15 ais a free distal end which is inserted and placed in the passage 11 ofthe pipe part 12. The rotary shaft 15 is supported in cantileverconfiguration through two bearings arranged apart from each other, thatis, a first bearing 37 and a second bearing 38, so that the rotary shaft15 is rotatable with respect to the valve housing 35. The first bearing37 and the second bearing 38 are each constituted of a ball bearing.Those first and second bearings 37 and 38 are placed between the valveelement 14 and the main gear 41 in the direction of the central axis Lsof the rotary shaft 15 to rotatably support the rotary shaft 15. In thepresent embodiment, the first bearing 37 is located at a position on aside close to the main gear 41 relative to the second bearing 38. Thevalve element 14 is fixed by welding to the pin 15 a in the distal endportion of the rotary shaft 15 and is placed in the passage 11.

The end frame 36 is secured to the valve housing 35 with a plurality ofclips 39 (see FIGS. 2 and 3). As shown in FIGS. 8 and 9, the main gear41 provided with a fan-shaped gear is fixed to the proximal end portion15 b of the rotary shaft 15. A return spring 40 that generates a returnspring force Fs1 (see FIG. 12t is provided between the valve housing 35and the main gear 41. The return spring force Fs1 is a force to rotatethe rotary shaft 15 in a valve-closing direction and to urge the valveelement 14 to a closing direction (that is, toward a position at whichthe valve opening degree θ which will be described later is “0”).

The return spring 40 is an elastic member made of wire wound in a coilshape and is provided, al both ends, with a far-side hook 40 a and anear-side hook 40 b. The far-side hook 40 a and the near-side hook 40 bare spaced at an interval of about 180° in a circumferential directionof the return spring 40. The far-side hook 40 a is located on a valvehousing 35 side (on a far-side of a drawing sheet of FIG. 11) so that itcontacts a spring hook part 35 c (sec FIG. 19) of the valve housing 35.In contrast, the near-side hook 40 b is located on a main gear 41 side(on a near-side of the drawing sheet of FIG. 11) so that it contacts aspring hook part 41 c of the main gear 41.

As shown in FIGS. 8 to 11, the main gear 41 includes a full-closestopper part 41 a, a gear part 41 b, the spring hook part 41 c, a springguide pan 41 d, and others. In the circumferential direction (acounterclockwise direction in FIG. 11) of the main gear 41, thefull-close stopper part 41 a, the gear part 41 b, and the spring hookpart 41 c are arranged in this order. The main gear 41 is integrallyprovided with the rotary shaft 15 and is configured to receive driveforce generated by the motor 32. The full-close stopper part 41 a is apart that abuts on the full-close stopper part 35 b of the valve housing35 when a valve opening degree θ is 0. The main gear 41 is one exampleof a “drive force receiving part” in the present invention.

The valve opening degree θ is a rotation angle of the rotary shaft 15rotated about the central axis Ls and corresponds to a rotation angle ofthe main gear 41, and an opening angle of the valve element 14. In otherwords, the time when the valve opening degree θ is 0 represents the timewhen the rotation angle of the rotary shaft 15 is a minimum angle withina rotatable range of the rotary shaft 15. FIGS. 8 to 11 show the timewhen the valve opening degree θ is 0.

As shown in FIG. 11, the gear part 41 b meshes with a small-diametergear 42 b of an intermediate gear 42. The spring hook part 41 c contactswith the near-side hook 40 b of the return spring 40 and receives thereturn spring force Fs1 from the near-side hook 40 b (see FIG. 12).

As shown in FIG. 9, the spring guide pan 41 d is placed in the coiledreturn spring 40 to support the return spring 40. The spring guide part41 d is provided integral with the rotary shaft 15 at a portion locatedclose to the proximal end 15 b of the rotary shaft 15.

The main gear 41 includes a recess 41 e in which a magnet 46 having asubstantially disk shape is mounted as shown in FIG. 9. Therefore, whenthe main gear 41 rotates together with the valve element 14 and therotary shaft 15, the magnet 46 is also rotated, changing a magneticfield of the magnet 46. This change in the magnetic field of the magnet46 is detected by a rotation angle sensor (not illustrated), so that therotation angle of the main gear 41 is detected as the opening degree ofthe valve element 14, that is, the opening degree of the main gear 41.

As shown in FIG. 8, the motor 32 is accommodated and fixed in a holdingcavity 35 a formed in the valve housing 35. The motor 32 generates adrive force to rotate the rotary shaft 15 in a valve opening directionand in a valve closing direction. The motor 32 is drivingly coupled tothe rotary shaft 15 through the speed reducing mechanism 33 to operatethe valve element 14 to open and close. Specifically, an output shaft 32a (see FIG. 10) of the motor 32 is fixedly provided with a motor gear43. This motor gear 43 is drivingly coupled to the main gear 41 throughthe intermediate gear 42 to transmit the drive force.

The intermediate gear 42 is a double gear having a large-diameter gear42 a and the small-diameter gear 42 b and is rotatably supported by thevalve housing 35 through a pin shaft 44. The diameter of thelarge-diameter gear 42 a is larger than the diameter of thesmall-diameter1 gear 42 b. The large-diameter gear 42 a is drivinglyengaged with the motor gear 43, while the small-diameter gear 42 b isdrivingly engaged with the main gear 41. In the present embodiment, eachof the main gear 41, the intermediate gear 42, the motor gear 43,constituting the speed reducing mechanism 33, is made of resin material.Weight saving is thus achieved in the present embodiment.

The motor 32 is one example of a “drive mechanism” in the presentinvention. Further, the intermediate gear 42 (a drive transmission part)transmits the drive force of the motor 32 to the rotary shaft 15.

In the integrated valve 181 configured as above, even though the detailswill be mentioned later, when the motor 32 is energized from such avalve-closed state as shown in FIG. 4 (a state where the entirecircumference of the seal surface 18 of the valve element 14 is incontact with the entire circumference of the seat surface 17 of thevalve seat 13), the force pushing the gear teeth (the motor drive forceFm1 (see FIG. 14)) is exerted on the main gear 41, thereby moving thevalve element 14 in a direction toward the valve seat 13 by theprinciple of leverage (see FIG. 15). Thereafter, when the drive voltage(current) applied to the motor 32 is gradually raised, the output shaft32 a and the motor gear 43 are rotated in a forward direction (i.e., adirection to open the valve element 14) and this rotation is reduced inspeed by the intermediate gear 42 and then transmitted to the main gear41. Accordingly, the valve element 14 is opened against the returnspring force Fs1 that is generated by the return spring 40 and thaturges (he valve element 14 in the valve closing direction, thus openingthe flow passage 11 (see FIGS. 16 and 18). Thereafter, when the drivevoltage applied to the motor 32 is maintained at a constant level in theprocess of opening the valve element 14, the motor drive force Fm1 andthe return spring force Fs1 become balanced with each other at theopening degree of the valve element 14 at that time, so that the valveelement 14 is held at a predetermined opening degree.

More details of the operations of the integrated valve 181 in thepresent embodiment will be described below. During non-operation of themotor 32 that is not energized (i.e., while the motor 32 is stopped),the valve opening degree θ is 0, that is, the integrated valve 181 is inthe valve-closed state. At that lime, as shown in FIG. 11, thefull-close stopper part 41 a of the main gear 41 contacts with thefull-close stopper part 35 b of the valve housing 35.

In this regard, the relationship of forces in terms of a circumferentialdirection of, or around, the rotary shaft 15 is considered as below. Asshown is FIG. 12, the spring hook part 41 c of the main gear 41 recievesthe return spring force Fs1 from the near-side hook 40 b of the returnspring 40. As shown in FIG. 12 in a rectangular of Cartesian coordinatesystem consisting of an origin represented by the central axis Ls of therotary shaft 15m an x-axis represented by a horizontal line, and ay-axis represented by a vertical line, a first quadrant is a partdefined by a +x axis and a +y axis, a second quadrant is a part definedby a −x axis and th +y axis, a third quadrant is a part defined b the −xaxis and a −y axis, and a fourth quadrant is a part defined by the +xaxis and the −y axis. At that time, the far-side hook 40 a and thefull-close stopper part 41 a are placed in a position corresponding tothe first quadrant, and the near-side hook 40 b and the spring hook part41 c are placed in a position corresponding to the third quadrant.

Herein, based on the principle of leverage, a fulcrum, or a pivot point,is set in the full-close stopper part 41 a, a point of effort is set inthe spring hook part 41 c, and a point of load is set in a middle partbetween th full-close stopper part 41 a and the spring hook part 41 c.Thus, the return spring force Fs1 applied to the spring hook part 41 ccauses a force Fs2 to act on the middle part between the full-closestopper part 41 a and the spring hook part 41 c. This is expressed by:“Force Fs2”=2×“Return spring force Fs1”. In FIG. 12, the distancebetween the full-close stopper part 41 a and the spring hook part 41 cis set to “2R”.

At that time, the relationship of forces in terms of a cross section ofthe rotary shaft 15 taken along the central axis Ls is also consideredas below. A +y direction component of the force Fs2 is a component forceFs3 as shown in FIG. 13. The +y direction represents a directionperpendicular to the central axis Lj direction of the first bearing 37and the second bearing 38 (the x direction ) and a direction towardwhich the valve seat 13 is placed relative to the valve element 14 (anupward direction on the drawing sheets of FIGS. 12 and 13). This isexpressed by: “Component force Fs3”=“Force Fs2”×“sin θ1”. The angle θisan angle formed between the arrangement direction in which thefull-close stopper part 41 a and the spring hook pan 41 c are arrangedand the x direction as shown in FIG. 12.

This component force Fs3 causes a force Fs4 (separating-direction urgingforce) to act on the spring guide pan 41 d in the +y direction. This isexpressed by: “Force Fs4”=“Component force Fs3”×Lb/La. In this way, theforce Fs4 is a force that is caused by the return spring force Fs1 andacts in a direction perpendicular to the central axis Lj of the firstbearing 37 and the second bearing 38. The distance La is a distance froma position in which the first bearing 37 is placed to a position onwhich the force Fs4 acts in the x direction. The distance Lb is adistance from the position where the first bearing 37 is placed to aposition on which the force Fs3 acts in the x direction.

When the force Fs4 acts in the +y direction at the position of thespring guide part 41 d, the rotary shaft 15 integral with the springguide pan 41 d is caused to turn and incline clockwise in FIG. 13 aboutthe first bearing 37 serving as the fulcrum. Accordingly, by theprinciple of leverage, the main gear 41 provided in the proximal end 15b of the rotary shaft 15 is moved in the +y direction, while the valveelement 14 provided on the pin 15 a of the rotary shaft 15 is moved inthe −y direction. Therefore, the valve element 14 is moved in adirection away from the valve seat 13 (a separating direction). In theabove manner, during the time when the motor 32 is not operated and theintegrated valve 181 is in the valve closed slate, the valve element 14is moved by the force Fs4 in a direction to separate from the valve seat13. At that time, the rotary shaft 15 is stopped by the second bearing38.

In the present embodiment, at that time, the valve element 14 is incontact with the rubber seat 21 (a scaling member) provided in the valveseat 13 as shown in FIG. 13. More concretely, as shown in FIG. 21, thevalve element 14 contacts the leading end of a deformable portion 21 a(a bead portion) of the rubber seat 21. In this state, the valve element14 is in contact with the leading end of the deformable portion 21 aover its entire circumference and the deformable portion 21 a is onlydeformed by a slight amount. In this manner, since the rubber seat 21seals between the valve seat 13 and the valve element 14, the integratedvalve 181 can enhance the sealing property with a simple structure.Herein, the integrated valve 181 is demanded for a sealing function toavoid suction of air into the fuel cell 111 during stop of a vehicle inwhich the fuel cell system 101 is mounted. In the present embodiment,for such a demanded sealing function of the integrated valve 181, therubber seat 21 seals between the valve seat 13 and the valve element 14.

At that time, furthermore, the valve element 14 is located at a positionrepresented by a point P1 a in FIG. 20 showing the relationship betweenthe valve opening degree θ and the open area S. Herein, the time “whenthe integrated valve 181 is in a valve-closed state” represents the timewhen the valve opening degree θ (the opening degree of the valve element14) is 0, that is, the time when the rotation angle of the rotary shaft15 is an angle during full closing (the minimum angle within therotatable angle of the rotary shaft 15).

Thereafter, during operation of the motor 32, namely, when the motor 32is energized, the motor drive force Fm1 acts from the small-diametergear 42 b (see FIG. II) of the intermediate gear 42 to the gear part 41b (sec FIG. 11) to rotate the main gear 41. When seen from the forcerelationship in terms of the circumferential direction of the rotaryshaft 15 at that time, the motor drive force Fm1 acts in the −ydirection as shown in FIG. 14. This −y direction is a perpendiculardirection to the central axis Lj direction (The x direction) of thefirst bearing 37 and the second bearing 38 and corresponds to adirection toward which the valve element 14 is placed relative to thevalve seat 13 (a downward direction in the drawing sheets of FIGS. 12and 13).

The motor drive force Fm1 causes s force Fm2 to act in the −y directionat the position of the central axis La of the rotary shaft 15. Further,when seen from the force relationship in terms of the cross section ofthe rotary shaft 15 taken along the central axis Ls, a force Fm3(seating-direction urging force) acts in the −y direction at theposition of the spring guide part 41 d as shown in FIG. 15. This isexpressed by: “Force Fm3”=“Force Fm2”×Lb/La. During operation of themotor 32, in the above manner, the force Fm3 is generated. This forceFm3 is a force that is caused by The motor drive force Fm1 and that actsin a direction perpendicular to the central axis Lj of the first bearing37 and the second bearing 38. The force Fm3 causes the rotary shaft 15to turn and incline about the first bearing 37 serving as the fulcrum,thereby urging the valve element 14 in a direction toward the valve seat13.

As shown in FIG. 15, when the force Fm3 becomes larger than the forceFs4, the rotary shaft 15 integral with the spring guide part 4 Id of themain gear 41 is caused to turn and incline counterclockwise in FIG. 14about the First bearing 37 serving as the fulcrum. Accordingly, by theprinciple of leverage, the main gear 41 is moved in the −y direction,while the valve element 14 moves in the +y direction. Therefore, thevalve element 14 is moved in a direction toward the valve seat 13 (aseating direction) by the force Fm3.

In the present embodiment, at that time, the deformable portion 21 a ofthe rubber seat 21 is pressed and deformed by the valve element 14.However, a deformation amount of this deformable portion 21 a is smallerthan a deformation amount of the deformable portion 21 a when it isplastically deformed. That is, the deformable portion 21 a iselastically deformed, but is not plastically deformed.

At that time, the the valve element 14 is located at a positionrepresented by a point P1 b in FIG. 20 showing the relationship betweenthe valve opening degree θ and the open area S.

Thereafter, when the drive voltage to be applied to the motor 32 risesand thus the motor drive force Fm1 become large, the rotary shaft 15 iscaused to further turn and incline counterclockwise in FIG. 16 about thefirst bearing 37 serving as the fulcrum. Accordingly, the main gear 41is further moved in the −y direction, while the valve element 14 isfurther moved in the +y direction. At that time, the rotary shaft 15 isrotated about the central axis Ls, so that the valve opening degree θ(the rotation angle of the rotary shaft 15) becomes “α” (see FIG. 17)and the open area S increases. In this state, the full-close stopperpart 41 a of the main gear 41 separates from the full-close stopper part35 b of the valve housing 35 as shown in FIG. 17. The rotary shaft 15 isstopped by the second bearing 38 as shown in FIG. 16. The valve element14 at that time is located at a position represented by a point P1 c inFIG. 20 showing the relationship between the valve opening degree θ andthe open area S.

Thereafter, as the motor drive force Fm1 further becomes larger, therotary shaft 15 is further rotated about the central axis Ls. Thiscauses the valve element 14 to separate from the valve seat 13 as shownin FIG. 18, further increasing the open area S. At that time, the valveopening degree 9 becomes “β” (see FIG. 19). The valve element 14 at thattime is located at a position represented by a point P1 d in FIG. 20showing the relationship between the valve opening degree U and the openarea S. In the above manner, the valve opening operation of theintegrated valve 181 by the motor drive force Fm1 is performed.

In the present embodiment, the integrated valve 181 includes the two,first bearing 37 and second bearing 38. Instead of these First andsecond bearings 37 and 38, a single bearing may be installed or three ormore bearings may be installed.

A conceivable modified example is to use a rubber seat 21 shown in FIG.22 or 23. As shown in FIG. 22, a rubber seat 21 has a lip-sealconfiguration that a deformable portion 21 a has a lip-like shape (aprotruding shape which is bendable when pressed by the valve element14). As shown in FIG. 23, on the other hand, a rubber seat 21 has acombination configuration of a lip seal and a bead that a deformableportion 21 a has a lip-like shape and is formed with a bead 21 b (aprojection which can come into close contact with the valve element 14).The rubber seat 21 may be provided in the valve element 14 instead ofthe valve seat 13.

The integrated valve 181 configured as above in the present embodimentgenerates the force Fs4 during non-operation of the motor 32. This forceFs4 is a force that is caused by the return spring force Fs1 and thatacts in a perpendicular direction to the central axis Lj of the firstbearing 37 and the second bearing 38. The force Fs4 causes the rotaryshaft 15 to incline about the first bearing 37 serving as the fulcrum,thereby urging the valve element 14 in the direction away from the valveseat 13. Furthermore, the rubber seat 21 is provided in either one ofthe valve element 14 or the valve seat 13 to seal between the valveelement 14 and the valve seat 13 during non-operation of the motor 32.

In the above way, the rubber seat 21 closes or seals between the valveseal 13 and the valve element 14. Thus, the integrated valve 181 canachieve an enhanced sealing property with a simple structure.

In the present embodiment, moreover, the rubber seal 21 includes thedeformable portion 21 a with a leading end which can come into contactwith the valve element 14 during non-operation of the motor 32 and canbe deformed when pressed by the valve element 14 during operation of themotor 32. A deformation amount of the deformable portion 21 a duringoperation of the motor 32 is smaller than a deformation amount of thedeformable portion 21 a when it is plastically deformed. Accordingly,the deformable portion 21 a of the rubber seat 21 is not excessivelypressed by the valve element 14 and thus abrasion of the rubber seat 21can be reduced. In the case where the rubber seat 21 is provided in thevalve element 14, the leading end of the deformable portion 21 acontacts the valve seat 13 during non-operation of the motor 32 and ispressed and deformed against the valve seat 13 during operation of themotor 32.

The eccentric valve of the invention is also applicable to the sealingvalve 174 and the bypass valve 191 in the air system 113 of the fuelcell system 101.

Second Embodiment

Next, a second embodiment will be described in which similar oridentical components or parts to those in the first embodiment areassigned the same reference signs as those in the first embodimentwithout repetition of their explanation. The following description ismade with a focus on differences from the first embodiment.

In the present embodiment, after power generation in the fuel cell 111is stopped, the integrated valve 181 is closed, but the motor 32 is notstopped immediately. The motor 32 is kept operating to press the valveelement 14 against the rubber seat 21 to establish a scaling statebetween them and thereafter the motor 32 is stopped to keep the scalingstate.

Therefore, the controller 201 executes a control based on a controlflowchart shown in FIG. 26 (FC air integrated-valve control). Thecontroller 201 firstly determines whether a FC stack power generationstop request is present (step 51). Herein, the “FC stack powergeneration stop request” is a request for stop of power generation inthe fuel cell 111. When the FC stack power generation stop request ispresent (step S1: YES), the controller 201 reads a stack pressure STP(step S2), executes scaling-valve closing control (step S3), and turnsthe sealing valve 174 to an OFF position, namely, turns off, or stops,energization of a drive mechanism of the sealing valve 174 (step S4) (oexecute integrated-valve closing control (step S5). Herein, the “stackpressure STP” is internal pressure of the fuel cell 111. The“sealing-valve closing control” is control of closing the scaling valve174. Further, the “integrated-valve closing control” is control ofclosing the integrated valve 181.

Successively, the controller 201 determines whether the slack pressureSTP is equal to or less than a predetermined pressure a (a predeterminednegative pressure) (step S6). When the stack pressure STP is equal to orless than the predetermined pressure a (step S6: YES), the controller201 turns off energization of the motor 32 of the integrated valve 181,thereby switching the motor 32 from the operation slate to thenon-operation state (step S7), and turns off a power supply of an ECU(ECU for sealing function control) (step S8). Herein, the predeterminedpressure a is a negative pressure, namely, is lower than atmosphericpressure.

When the stack pressure STP decreases to be equal to or less than thepredetermined pressure a, the controller 201 stops energization of themotor 32 of the integrated valve 181 to switch the motor 32 from theoperation stale to the non-operation stale. Specifically, the motor 32is to be switched from the operation state to the non-operation state asbelow. Firstly, while the internal pressure of the fuel cell 111 ishigher than the predetermined pressure a, energization of the motor 32is kept to press the valve element 14 against the rubber seat 21 toestablish a sealing state between them. Then, when the internal pressureof the fuel cell 111 becomes equal to or less than the predeterminedpressure a, energization of the motor 32 is stopped, allowing the valveelement 14 to contact the rubber seat 21 under the negative internalpressure of the fuel cell 111 to establish a sealing state between them.

In step S6, when the stack pressure STP is higher than the predeterminedpressure a (step S6: NO), energization of the integrated valve 181 iskept turned on, that is, the motor 32 of the integrated valve 181continues to be energized and kept operating (step S9), and the powersupply of the ECU is kept turned on (step S10).

In step S1, when the FC stack power generation stop request is notpresent (step S1: NO), the controller 201 executes a control accordingto power generation requests for the sealing valve 174, the integratedvalve 181, and the bypass valve 191 (step S11).

When the control based on the foregoing control flowchart is executed,for example, a control represented by a control time chart shown in FIG.27 is performed. As shown in FIG. 27, after the FC stack powergeneration stop request is made at time T1, when the slack pressure STPbecomes equal to or less than the predetermined pressure a at time T2,energization of the motor 32 of the integrated valve 181 is stopped.

According to the present embodiment, when the motor 32 is to be switchedfrom the operation state to the non-operation state, the motor 32 isswitched to the non-operation state after the pressure on the valveelement 14 on the side facing to the valve seat 13, that is, the stackpressure STP, reaches the predetermined pressure a. In this manner, themotor 32 is operated until the stack pressure STP reaches thepredetermined pressure a and, after the stack pressure STP has reachedthe predetermined pressure a, the motor 32 is brought into thenon-operation stale to allow the valve element 14 to move toward thevalve seal 13 by utilization of the negative pressure generated in thefuel cell 111. Even when the rubber seat 21 has worn, the scalingproperty, or strength, between the valve seat 13 and the valve element14 during valve closing can be enhanced. Further, during stop of powergeneration in the fuel cell 111, even when the motor 32 of theintegrated valve 181 is turned in the non-operation stale, the valveelement 14 is allowed to move toward the valve seat 13 by utilization ofthe negative pressure generated in the fuel cell 111. Accordingly,during non-operation of the motor 32, the scaling property between thevalve seat 13 and the valve element 14 during valve closing can beenhanced.

Third Embodiment

Next, a third embodiment will be described below. Similar or identicalcomponents or parts to those in the first and second embodiments areassigned the same reference signs as those in those embodiment withoutrepetition of their explanation. The following description is given witha focus on differences from the first and second embodiments.

In the present embodiment, during operation of the motor 32, the controlis executed in a sealing control mode and a pressure-regulating mode.Herein, the scaling control mode is a mode of controlling the rotationof the valve element 14 while the valve element 14 at an opening degreenear a fully-closed position. This sealing control mode will beperformed for instance during stop of a vehicle in which the fuel cellsystem 101 is mounted. The pressure-regulating mode is a mode ofcontrolling the open area S of the valve hole 16 to regulate a flow rateof air. In this pressure-regulating mode, the valve element 14 iscontrolled with a larger opening degree than that in the sealing controlmode. This pressure-regulating mode will be performed for example duringrunning of a vehicle in which the fuel cell system 101 is mounted.

Therefore, the controller 201 executes a control based on the controlflowchart shown in FIG. 28 (FC air integrated-valve control). Firstly,the controller 201 takes a stack supply target air amount (a targetamount of air to be supplied to a FC stack) TSTGa (step S101), andcontrols an injection amount of the air pump 172 to an amount accordingto the stack supply target air amount TSTGa (step S102). The controller201 further takes a stack pressure STP (step S103), and takes on actualintegrated-valve opening degree ata, that is, a current actual openingdegree of the valve element 14 of the integrated valve 181 (step S104).

Subsequently, the controller 201 determines whether an integrated-valvepressure-regulating request is present or absent (step S105). When theintegrated-valve pressure-regulating request is present (step S105:YES), it is determined whether a XACVC flag is 0 or not (step S106).This XACVC flag is a determination flag for the angle A.

When the XACVC flag is 0 (step S106: YES), the controller 201 judges ifthe actual integrated-valve opening degree ata is equal to or largerthan the angle A (step S107). Herein, the time when the actualintegrated-valve opening degree ata is the angle A represents the timewhen the opening degree of the valve element 14 of the integrated valve181, that is, the valve opening degree θ (the rotation angle of therotary shaft 15 and the rotation angle of the main gear 41) is the angleA as shown in FIG. 24. At that time, as show in FIG. 24, the valveelement 14 and the rubber seat 21 are not in contact with each other.

When the actual integrated-valve opening degree ata is equal to orhigher than the angle A (step S107: YES), that is, when thepressure-regulating mode in which the valve element 14 and the rubberseat 21 are out of contact with each other, the XACVC flag is turned to1 (step S108). Then, a target integrated-valve opening degree tpcta anda target bypass-valve opening degree tbta are determined in order tocontrol a stack supply air amount STGa to the stack supply target airamount TSTGa (step S109).

The controller 201 then determines whether or not the targetintegrated-valve opening degree tpcta is equal to or higher than theangle A (step S110). When the target integrated-valve opening degreetpcta is equal to or higher than the angle A (step S110: YES), thecontroller 201 controls the opening degree of the valve element 14 ofthe integrated valve 181 to the target integrated-valve opening degreetpcta with high responsivity. Specifically, the controller 201 increasesthe rotation speed of the valve element 14 of the integrated valve 181and adjusts the opening degree of the valve element 14 to the targetintegrated-valve opening degree tpcta, and controls the bypass valve 191to the target bypass valve opening degree tbta with high responsivity(step S111). The pressure-regulating mode is thus performed when thevalve element 14 and the rubber seat 21 are in a non-contact mate witheach other.

In step S105, when the integrated-valve pressure-regulating request isabsent (step S105: NO), the controller 201 determines whether or not theXACVC flag is 1 (step S112). When the XACVC flag is 1 (step S112: YES),it is determined whether or not the actual integrated-valve openingdegree ata is smaller than the angle A (step S113) When the actualintegrated-valve opening degree ata is smaller than the angle A (stepS113; YES), the controller 201 turns the XACVC flag to 0 (step S114) andcontrols the integrated valve 181 to be fully closed by integrated-valveslow closing control (step S115). To be concrete, in the scaling controlmode where the actual integrated-valve opening degree ata is less thanthe angle A (i.e., when the opening degree of the valve element 14 isclose to a fully-closed position), the controller 201 causes theintegrated valve 181 to be fully closed by decreasing the rotation speedof the valve element 14. In this manner, the rotation speed of the valveelement 14 in the sealing control mode is made slower than the rotationspeed of the valve element 14 in the pressure-regulating mode.

In step S106, when the XACVC flag is not 0 (step S106: NO), theprocessing in step S109 is carried out.

In step S107, when the actual integrated-valve opening degree ata isless than the angle A (step S107; NO), integrated-valve slow openingcontrol is executed, that is, the valve-opening control is conducted bydecreasing the rotation speed of the valve element 14 (step S116), andthe processing in step S106 is carried out. Specifically, in the sealingcontrol mode where the actual integrated-valve opening degree ata isless than the angle A (i.e., when the opening degree of the valveelement 14 is close to a fully-closed position), the integrated valve181 is opened by decreasing the rotation speed of the valve element 14.

In step S110, when the target integrated-valve opening degree tpcta isless than the angle A (step S110; NO), the processing in step S111 isperformed by assigning the target integrated-valve opening degree tpctato the angle A (step S117).

In step S112, when the XACVC flag is not 1 (step S112: NO), theprocessing in step S115 is performed.

In step S113, when the actual integrated-valve opening degree ata isequal to or higher than the angle A (step S113: NO), integrated-valvequick closing control is executed, that is, the valve-closing control isconducted by increasing the rotation speed of the valve element 14 (stepS118). Further, the processing in step S112 is carried out.

When the control based on the foregoing control flowchart is executed,for example, a control represented by a control time chart shown in FIG.29 is performed. As shown in FIG. 29, scaling slow changing control isexecuted at time T11 and lime T15. Specifically, the integrated-valveslow opening control is conducted at time T11 and the integrated-valveslow closing control is conducted at time T15. Further,pressure-regulating high response control 13 executed at time T12 andtime T14. Specifically, the opening degree of the valve element 14 ofthe integrated valve 181 is controlled with high responsivity. Further,at time T11 and T14, bypass high-response control is performed, that is,the opening degree of a valve element of the bypass valve 191 iscontrolled with high responsivity.

According to the present embodiment, the control mode to be performedduring operation of the motor 32 includes the pressure-regulating modeand the sealing control mode. In the pressure-regulating mode, the valveelement 14 and the rubber seat 21 are in a non-contact state with eachother. In the pressure-regulating mode which will be performed with highfrequency, the valve element 14 and the rubber seal 21 are not incontact with each other. This can minimize the number of times the valveelement 14 and the rubber seat 21 slide against each other. Thus,abrasion or wear of the rubber seat 21 can be reduced.

The rotation speed of the valve element 14 in the sealing control modeis slower than the rotation speed of the valve element 14 in thepressure-regulating mode. Accordingly, the sliding intensity of thevalve element 14 with respect to the rubber seat 21 in the scalingcontrol mode can be reduced, thus enabling reduction in abrasion or wearof the rubber seat 21.

Fourth Embodiment

Next, a fourth embodiment will be described below, in which similar oridentical components or parts to those in the first through thirdembodiments are assigned the same reference signs as those in the firstthrough third embodiments without repetition of the details thereof. Thefollowing description is given with a focus on differences from thefirst through third embodiments.

In the present embodiment, in a vehicle mounted with the fuel cellsystem 101, when a regenerative brake request is made and powergeneration of the fuel cell 111 is stopped, surplus electric powergenerated by reaction between hydrogen gas and oxygen gas remaining inthe fuel cell 111 is consumed for driving the air pump 172 while abattery (not shown) is in a full-charged state. At that time, theintegrated valve 181 is closed, but a leakage amount of air in theintegrated valve 181 does not have to be 0. Therefore, when theregenerative brake request is made, the integrated valve 181 is notcontrolled to be fully closed but is controlled to bring the valveelement 14 in a position where it begins to contact the rubber seat 21(e.g., a position shown in FIG. 15) so that the valve element 14 ispressed against the rubber seat 21 with low pressure. Specifically, theopening degree of the valve element 14 is adjusted to an angle B whichis larger than the angle set for full closing and smaller than the angleA.

Therefore, the controller 201 executes a control based on a controlflowchart shown in FIG. 30 (FC air control). When an ignition switch IGis ON (step S201: YES), the controller 201 determines whether or not apower generation request is present (step S202). When the powergeneration request is present (step S202: YES), it is further determinedwhether or not the regenerative brake request is present (step S203).When the regenerative brake request is present (step S203: YES), theopening degree of the valve element 14 of the integrated valve 181 isadjusted to the angle 13 (step S204), the bypass valve 191 is controlledto be fully closed (step S205), the air pump 172 is controlled tooperate at the number of rotations for a regenerative mode (step S206),and a XEB Hag is turned to 1 (step S207).

In this way, when the regenerative brake request is made and the airpump 172 is thus operated, the opening degree of the valve element 14 isheld at the angle B. This angle B is an opening degree at some pointwithin an opening degree range in the sealing control mode and is largerthan the angle set for full closing and smaller than the angle A. TheXEB flag is a regenerative brake control flag, which is set to 0 whenthe regenerative brake is not performed or set to 1 when theregenerative brake is in operation.

In step S202, when the power generation request is absent (step S202:NO), the controller 201 stops the air pump 172 (step S208), performslull closing control of the sealing valve, the integrated valve, and thebypass valve (step S209 to S211), and turns the XEB nag to 0 (stepS212).

In step S203, when the regenerative brake request is absent (step S203:NO), the controller 201 determines whether or not the XEB flag is 1(step S213). When the XEB flag 1, that is, when a return request ispresent (step S213: YES), the controller 201 immediately performs fullclosing control of the bypass valve 191, the valve-opening control, andthe valve-closing control (step S214), the XEB flag is turned to 0 (stepS215), and further the processing in step S213 is performed.

In step S213, when the XEB flag is not 1, that is, when a running powergeneration request (a request for power generation during running) ispresent (step S213: NO), an output request is taken (step S216; andscaling-valve full-opening control is executed (step S217) to controlthe integrated-valve opening degree, the bypass valve opening degree,and the number of rotations of the air pump according to the outputrequest (step S218).

When the control based on the foregoing control flow charge areexecuted, for example, a control represented by a control time chartshown in FIG. 31 is executed. As shown in FIG. 31, at time T25,regenerative control is conducted. Specifically, at time T25, theopening degree of the valve element 14 of the integrated valve 181 isadjusted to the angle B.

According to the present embodiment, when the air pump 172 is operatedin response to the regenerative brake request, the opening degree of thevalve element 14 is held at the angle B. Accordingly, the full closingcontrol of the integrated valve 181 is not executed when theregenerative brake request is frequently made, but is executed only whena vehicle is completely stopped. Therefore, the valve element 14 and therubber seat 21 can be prevented from frequently sliding against eachother. Thus, while wear of the rubber seat 21 is suppressed, surpluselectric power generated when the regenerative brake request is made canbe consumed for operation of the air pump 172.

The foregoing embodiments are mere examples and do not give anylimitations to the present invention. The present invention may beembodied in other specific forms without departing from the essentialcharacteristics thereof. For instance, the rotary shaft 15 may besupported at both ends by the first bearing 37 and another bearing (notshown) separately provided on an opposite side of the valve element 14.

REFERENCE SIGNS LIST

-   2 Valve unit-   3 Drive mechanism unit-   11 Passage-   13 Valve seat-   14 Valve element-   15 Rotary shaft

15 a Pin

-   15 b Proximal end portion-   16 Valve hole-   17 Seat surface-   18 Seal surface-   21 Rubber seat-   21 a Deformable portion-   21 b Bead-   32 Motor-   35 b Full-close stopper-   35 c Spring hook part-   37 First bearing-   38 Second bearing-   40 Return spring-   40 a Far-side hook-   40 b Near-side hook-   41 Main gear-   41 a Full-stopper-   41 b Gear part-   41 c Spring hook part-   41 d Spring guide part-   101 Fuel cell system-   111 Fuel cell-   112 Hydrogen system-   113 Air system-   162 Air exhaust passage-   174 Sealing valve-   181 Integrated valve-   191 Bypass valve-   Ls Central axis (of rotary shaft)-   Lv Central axis (of valve element)-   Lj Central axis (of bearing)-   Fs1 Return spring force-   Fs4 Force (Separating-direction urging force)-   Fm1 Motor drive force-   Fm3 Force (Seating-direction urging force)-   θ Valve opening degree

1. An eccentric valve comprising: a valve seat including a valve holeand a seat surface formed al an edge of the valve hole; a valve elementformed with a seal surface on an outer periphery corresponding to theseat surface; and a rotary shaft integrally provided with the valveelement to route the valve element, the rotary shaft having a centralaxis extending in parallel to a radial direction of the valve element,the central axis of the rotary shaft being positioned eccentrically froma center of the valve hole in another radial direction of the valvehole, and the seal surface being positioned eccentrically from thecentral axis of the rotary shaft toward an extending direction of acentral axis of the valve element, wherein the eccentric valve furthercomprises: a drive mechanism configured to generate a drive force lorotate the rotary shaft in a valve opening direction; a drive forcereceiving part integrally provided with the rotary shaft and configuredlo receive the drive force; a bearing placed in a position between thevalve element and the drive force receiving part in a direction of thecentral axis of the rotary shaft to support the rotary shaft; and areturn spring configured lo generate a return spring force to rotate therotary shaft in a valve closing direction, wherein, during non-operationof the drive mechanism, the eccentric valve generates aseparating-direction urging force to cause the rotary shaft to inclineabout the bearing serving as a fulcrum and urge the valve element in adirection away from the valve seat, the separating-direction urgingforce being a force caused by the return spring force and acting in adirection perpendicular to a central axis of the bearing, either thevalve element or the valve seal is provided with a scaling member toseal between the valve element and the valve seat during non-operationof the drive mechanism, and the eccentric valve is configured to performa control mode during operation of the drive mechanism, the control modeincluding a pressure-regulating mode for controlling an open area of thevalve hole and a sealing control mode for controlling rotation of thevalve element near a fully-closed position of the valve element
 2. Theeccentric valve according to claim 1, wherein the sealing memberincludes a deformable portion having a leading end that comes intocontact with the valve element or the valve seat during non-operation ofthe drive mechanism and that is deformed when pressed by the valveelement or a valve seat during operation of the drive mechanism, and adeformation amount of the deformable portion during operation of thedrive mechanism is smaller than a deformation amount of the deformableportion when plastically deformed.
 3. The eccentric valve according toclaim 1, wherein when the drive mechanism is to be switched from anoperation state to a non-operation state, the drive mechanism isswitched to the non-operation state after a pressure on the valveelement on a side facing the valve seal, reaches a predeterminednegative pressure.
 4. The eccentric valve according to claim 1, whereina rotation speed of the valve element in the scaling control mode isslower than a rotation speed of the valve element in thepressure-regulating mode.
 5. The eccentric valve according to claim 1,wherein the valve element and the sealing member in thepressure-regulating mode are in a non-contact slate with each other. 6.The eccentric valve according to claim 1, wherein the eccentric valve isprovided with a passage through which air in a fuel cell system flows,and when the fuel cell system drives an air pump to control a flow rateof the air in response to a regenerative brake request, an openingdegree of the valve element is maintained at an opening degree within anopening degree range determined in the sealing control mode.